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SpaceX Makes Aerospace History With Successful Launch, Landing of a Used Rocket (theverge.com)
Eloking quotes a report from The Verge: After more than two years of landing its rockets after launch, SpaceX finally sent one of its used Falcon 9s back into space. The rocket took off from Cape Canaveral, Florida, this evening, sending a communications satellite into orbit, and then landed on one of SpaceX's drone ships floating in the Atlantic Ocean. It was round two for this particular rocket, which already launched and landed during a mission in April of last year. But the Falcon 9's relaunch marks the first time an orbital rocket has launched to space for a second time. SpaceX CEO Elon Musk appeared on the company's live stream shortly after the landing and spoke about the accomplishment. "It means you can fly and refly an orbital class booster, which is the most expensive part of the rocket. This is going to be, ultimately, a huge revolution in spaceflight," he said. "It's been 15 years to get to this point, it's taken us a long time," Musk said. "A lot of difficult steps along the way, but I'm just incredibly proud of the SpaceX for being able to achieve this incredible milestone in the history of space."
Major kudos to the SpaceX team! Thank you for letting me get to see the future.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
That's another few million saved per flight.
With this huge milestone down, the next big one is Falcon Heavy - with 3 of these boosters landing for reuse.
We are on the cusp of a new age of space - prices are going to drop like crazy, and Mars just got a whole lot cheaper to reach!
become politicians and try to enslave the population others take their money and move humanity forward. Imagine if more billionaires did this .
by TheSpoom (715771) Uncaring Linux user here. I have nothing to add to this but please continue. *munches popcorn*
Truly amazing and a real milestone in humanity reaching for the stars.
Well done!
Mimetics Inc. Twitter
You just may have re-ignited the dreams of a couple of generations.
So, yes, I wanted to be a space pirate! I will be downloading those so-called illegal copies of movies that haven't even been shown, by travelling at FTL speeds I will obtain those films a day before their worldwide premiere.
one owner. only been driven twice.
Bet your ass that rocket was gone over with a fine-toothed comb, at great expense.They won't have proven the economy of re-launching rockets until it's routine with zero to very few accidents and the finance numbers are in.
If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
My coworker is at their plant at the moment. I'll have to ask if he got to be in there with all the employees. So cool :)
The shuttle was planned to be reusable, in practice it was not. It took way too much refurb to get it flight ready again.
Good-bye
And so is this story. I posted it earlier:
https://slashdot.org/submissio...
"But they skimped on the maintenance, allowing tiles to get loose. Over time they loosened and fell off, resulting in major catastrophe."
Neither crash was caused by tiles falling off the Shuttle.
From Robert A. Heinlein, Excerpts from the Notebooks of Lazarus Long
Good thing that Elon Musk listens to experts. I believe those experts are telling him that he can't go to Mars.
After so many years of reading science fiction it's nice to see some of it becoming science fact. Please keep pushing ahead Elon.
With basically a new engine each time, very reusable.
The problems with tiles were not due to deferred maintenance. They were engineering problems with the adhesives, etc.
It also took a lot of work to refurbish the engines on the Shuttle. They had to be completely removed from the craft after each and every mission, disassembled, and a lot of parts replaced.
Bruce Perens.
Let me rephrase. We didnt save nearly as much money as we thought we would by re-using them. The cost to refurbish was ridiculously high. Yes they were 'reusable', but not in the way they were planned to be. WE would have gotten a lot more flights than 135 if they had been cheaper to refurbish.
Good-bye
That was more of a "recycled" system than a "reusable" one. The SRBs needed almost completely renewal after recovery, and the other boosters weren't reusable at all.
Put another way: the Shuttle was more expensive because it was "reusable." Falcon-9 is less expensive.
The SRBs fell, uncontrolled, into the ocean and were re-filled with firecracker stuff. It was always only marginally economical to reuse them. In contrast, the Falcon 9 is a liquid fueled rocket with on-board avionics, which soft-lands in a usable state. Its engine has been tested after landing, without any refurbishment at all.
The new goal is to turn around a booster and re-fly it in 24 hours.
Bruce Perens.
In addition to the corrections to your post concerning the tiles, the Shuttle orbiter was basically a second stage (at best, a 1.5 stage). A significant minority of the dry mass of the system. The SRBs were also "recovered", but A) they landed in saltwater, B) "landing" is being generous, they hit *hard*, C) solid rockets aren't just a "refill and reuse", you have to disassemble and recast. The net result is that reuse didn't really save any money on the SRBs.
The Shuttle's TPS was a big maintenance problem (not an issue for Falcon). The SSMEs were also pretty high maintenance. Shuttle had to build a whole huge ET each launch. And NASA has such huge amount of heavy infrastructure overhead.
It's hard to say how well reuse of Falcons will go at this point. But it should at the very least fare far better than the Shuttle system.
It's also worth noting that Falcon is only the start of SpaceX's plans. While they've learned what to do and what not to do from the Shuttle program, they want their experience with F9 and FH to influence their design of ITS and its support infrastructure.
Kneel Before Christ!
Did have some quite close calls, mind you.
Kneel Before Christ!
See above. The SRBs didn't so much land as hit the ocean at highway speeds, bob around in corrosive saltwater, have to be fished out, taken back, fully disassembled, recast, fully assembled, with a large fraction of the parts replaced.
If you want the airplane equivalent, it would be as if every plane flight, instead of landing, crashed into a mucky swamp and banged the plane up badly, ruining half the parts, and the whole airplane had to be broken down, large chunks of the plane replaced, and oh, instead of using jet fuel you have to open up the fuel tank, break it into pieces, and mould a non-extinguishable propellant into place before reassembling it.
This is, needless to say, not the model SpaceX is going for.
Kneel Before Christ!
Tiles getting loose and falling off had nothing to do with either shuttle accident.
The shuttle SRBs landed under parachute in the ocean and were towed back to land, refurbished, and relaunched on most flights.
"But they skimped on the maintenance, allowing tiles to get loose. Over time they loosened and fell off, resulting in major catastrophe."
What's your source for most of the parts on the srb's needing to be replaced? The srb's were made of aluminum and titanium, sea water is hardly corrosive to them. And they've been reusused for nearly 40 years.
The shuttle was an expensive learning system. Technology has advanced much since. The costs for orbital shots is much cheaper than two decades ago.
As far as I know NASA never skimped on tile maintence, it was one of the many reasons every shuttle flight was so damn expensive.
I read the internet for the articles.
"Refurbished" with the STS SRBs meant "completely gutted, rebuilt from the ground up reusing whichever parts could be", which is not equivalent to what SpaceX is doing. The salty sea water landing destroyed much of the boosters' components. The refurbishment wasn't particularly economical and did little to reduce the astronomical cost of STS launches. The external fuel tank was also completely discarded.
The one that broke up over Texas was due to tiles being damaged. They did not fall off but were struck allowing heat to destroy the shuttle. The other was due to a failing o-ring. A lot of things to go wrong with possible catastrophic consequences.
The Space Shuttle SSMEs are the highest performance rocket engines ever launched (by weight), and were reusuable. It really shouldn't be surprising they required some maintenance between flights.
The falcon first stage doesn't make it to orbit, so it is hardly an apples to apples comparison to the space shuttle.
Seeing as how the engines were saved and are planned to be used on Orion, you'll see more launches from them.
The adhesive worked fine for the FIRST flight. It was only over time and use that it failed.
The way you correct any problem caused by use of a vehicle is called MAINTENANCE. The proper maintenance routine for a shuttle would have involved testing the tiles to see if the adhesion was still good, and/or replacing them.
They did in fact replace tiles all the time, they simply failed to put in a good testing program, not understanding the issue of a loose tile hitting the left wing of the shuttle, damaging it enough to let hot air destroy it.
Poor maitenance was the cause. They knew that tiles fell off, they did not understand the risk this caused, and failed to properly maintain the shuttle in such a way that would have prevented loose tiles.
excitingthingstodo.blogspot.com
The solid rocket boosters the shuttle used were also first stage rockets that were reused. The use case was different, parts from different previous launches were mixed around and re-combined, but the bottom line is that first stage re-use has been around for more than 30 years.
Those boosters parachuted into the ocean, which is a much simpler approach than a soft landing. To many of us, simpler still means better. Yes, they hit the ocean hard and bobbed around in salt water, and it required a very extensive re-build because it was solid fuel based. There's nothing inherently "wrong" with any of that, and it was a design and approach that worked (with one VERY notable failure). This begs the question, why go through all the work for the soft landing?
If the metric here is simply re-usability, previous rocket makers solved that problem decades ago.
SpaceX's metric is probably cost, though.
That's a great metric, maybe the BEST metric, but it's not what the article is about. Disappointingly absent from TFA about today's launch was the cost to SpaceX to refurbish and test the rocket, although we know the process took 4 months. (Launch price and refurbishing cost are not related yet, SpaceX took a loss here to prove a point.)
It is pretty shitty to all the engineers who came before and accomplished great things to pretend their work never happened simply because a cost focused news blurb is less effective than "aerospace history."
Ice came off the external tank and damaged the carbon fiber left wing leading edge.
No tiles involved, but don't let being wrong stop your rant.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
"The way you correct any problem caused by use of a vehicle is called MAINTENANCE. "
Um, no. That's called engineering. You seem to be operating from a position of significant mental disadvantage.
wasnt loose tile that. it was ice coming off the external tank during launch.
reusable (and performant) like a top fuel dragster engine, yes.
those dragster engines get torn down and rebuilt after each run, too...
No, A big piece of fucking foam from the external tank broke loose (always happened from STS-1 and on...was considered an acceptable risk at the time) and this time the foam hit the leading edge of the wing(hottest part during reentry FYI) knocking a large hole in it. Maintenance had jack shit to do with it. And besides...any tile with any issue after it came back was replace...always....that is why is took so long and cost so much money each time it was launched/landed.
A great deal of technology went into the success of the re-useable rocket. I'm curious to know how much of that is shared. In bioscience, for instance, there is much sharing of information, presumably for the public good. Does Musk share his discoveries with other space programs?
We at Slashdot all have an interest in patents and copyright. We are of many opinions but seem generally antagonistic toward locking up Intellectual Property. Should space exploration developments be shared? How would that effect or offset the expensive research necessary to pull off this re-useable rocket success?
...omphaloskepsis often...
Wasn't ice either, it was foam insulation from the external fuel tank. A chunk about the size of a small briefcase from the left booster bi-pod support.
Foam insulation saturated in water ice.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Nope. You don't seem to understand the difference between maintenance and engineering. No amount of maintenance would have solved the problem of tiles falling off, because maintenance would have been re-doing the same failing materials and methods. It was necessary to re-engineer the tile system. The final version has an underlayment that protects the tiles from the thermal expansion of the metal shuttle skin, which would otherwise cause them to fall off, various tile compositions and coatings for areas of different stress, and some high-heat blankets, fabric panels, and felts for where tile would not conform to a shape. Also, tile did not hit the wing of the shuttle. Foam from the external tank insulation did.
Bruce Perens.
Not ice. Insulating foam.
Cold was a factor in the failure of the SRB o-rings in the first shuttle disaster, maybe that's what you are thinking of.
Bruce Perens.
Honestly, it was probably less economical to re-use them than to make new ones each launch if they had actually set up mass production of them. They were basically just large metal tubes with tang and clevis joints.
The srb's were made of aluminum and titanium, sea water is hardly corrosive to them
They were actually made of steel.
Don't forget the part where you ship all the pieces to Utah to do the refurbishing, then ship the assembled almost-bomb back to the launch site in Florida.
The new goal is to turn around a booster and re-fly it in 24 hours.
Which means it'll have to be the more difficult task of returning the 1st stage to the launch site as recovering it from the drone ship will take much too long.
Pain is merely failure leaving the body
Here's NASA's description of the process of retrieving & refurb'ing the SRBs
https://oce.jpl.nasa.gov/pract...
Pain is merely failure leaving the body
Engineering, maintenance, administration, isolation, they're all different methods to mitigate risk.
If you think only engineering exists, then you're the one lacking in knowledge.
The booster shell was mostly aluminium, but the motor segments were forged D6AC steel. Steps were taken to reduce saltwater ingress and corrosion, but it's difficult to prevent after a 50mph impact into the sea. They still had to rinse it, wash with detergent, disassemble and inspect every part (using visual, ultrasonic, and x-rays) for even slight corrosion or defects.
I dunno, I watched the webcast and that leeward fin will definitely need a new paint job. So, like I said, I dunno about 24hr turn around so far.
like 15 years ago i know who bruce perens was now i just know he's a guy who's known for doing something a while ago
Which means it'll have to be the more difficult task of returning the 1st stage to the launch site as recovering it from the drone ship will take much too long.
They'll launch it from the drone ship :)
that he didn't run.
Crickets...
A much simpler problem to solve and solids don't have the same performance.
So we launch tomorrow?
The shuttle was interrupted late in the design process by an outside organization that demanded and got large changes, slowing progress and adding cost.
because the new team decided to save 600 lb by leaving the paint off, not knowing that it was keeping the water out of the insulation.
I dunno, I watched the webcast and that leeward fin will definitely need a new paint job. So, like I said, I dunno about 24hr turn around so far.
In the press conference after the launch, Elon Musk specifically said that the grid fins would be made from titanium instead of aluminum on the final revision of the Falcon 9 so it would not suffer from that problem.
Slashdot your i and slashcross your t.
Not even close. There are several engines with higher thrust to weight ratio while having significantly more thrust, like F-1 or RD-170. The latter is the most powerful liquid fuelled engine ever built and actually also reusable, even though it never happened. SSME was more efficient (higher specific impulse) thanks to hydrogen fuel.
"It's such a fine line between stupid and clever" -- David St. Hubbins, Spinal Tap
You have created a false distinction, there is no difference between maintenance and engineering. If you do enough of one, you need less of the other.
A well engineered item needs less maintenance. A poorly engineered item needs more. They are exchangeable.
excitingthingstodo.blogspot.com
It's quite possible they're not aiming to reuse the same components on the same booster. It would be just as efficient to replace certain items (grid fins, legs, etc) an already refurbished component. Those components could be refurbished and swapped into a subsequent booster for relaunch.
Quite frankly, I don't think it matters if a booster contains the same reused parts or whether it contains reused parts from a different booster. The aim is to get a quick launch turn-around.
Ok, i see the problem here. You don't have a clue what youre talking about. The shuttle's thermal protection tiles didn't fall off and impact the wing. Insulation on the external tank did.
The shuttle was a learning curve. Having to replace windows every second flight due to micrometeorite impacts was not something that was expected for example.
It's also a bit of an argument against those people who push for mass production of a bleeding edge technology. Instead of having the dream of a few perfect space vehicles we had a number of space vehicles with exactly the same fault that had to be fixed or worked around at exactly the same time.
Space X are not in the situation of making a pile of identical rockets whether they want to or not so it's very likely that there will be a lot of incremental improvement.
IMHO part of the problem was five almost identical prototypes instead of incremental improvement of the basic design.
musk says a lot of things.. how about 9 out of 10 successfull landings first.
Yes he says a lot of things and he backs a huge number of them up. His company managed to launch and land a booster twice and they did it successfully on their first try at landing a used booster. Gives pretty good confidence that SpaceX can replicate the results. More work to do of course but unlike snarky slashdot posters, he's actually doing the work. What have you done to advance human kind today?
This is a huge stepping stone. Your cynicism is misplaced.
Interesting discussion. He made a comment there "economics don't make sense until next year". I assume that means the cost of refurbishment is currently more expensive than the value of the booster.
That would be more or less expected for the first iterations of any new project. Companies rarely make money on the early versions of a product because they are still working out the kinks and paying for the tooling and engineering. It will take them some time before it really starts to become profitable because they are still in the steep part of the learning curve and investment cycles. Normal and expected. If they are actually doing it and making a profit by next year then that is outstanding progress. (disclosure: I'm a cost accountant and a process engineer so I do this sort of analysis for a living)
exactly..
the F9 engines are more like Chevy Small Blocks.. run em over and over without doing anything.
"But they skimped on the maintenance, allowing tiles to get loose. Over time they loosened and fell off, resulting in major catastrophe."
Neither crash was caused by tiles falling off the Shuttle.
Challenger was caused the SRB's manufacturer cutting corners meaning that the O-Ring didn't function properly at low tempretures.
Columbia was caused by Insulation falling off the main fuel tank during launch and damaging the heat shield on one of the wings. This was largely because regulations required them to use a more environmentally insulation on the fuel tank which couldn't maintain the same structural integrity of the previous insulation. To quote Kermit the Frog "It isn't easy being green"
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
Gurps is somewhat famous around here for being a neutronium-dense idiot. He's not as entertaining as Khyber however, who seems to be a barely controlled under-medicated psychotic.
Challenger was caused the SRB's manufacturer cutting corners meaning that the O-Ring didn't function properly at low tempretures.
Minor quibble: the O-Ring performed as designed - it was just that the launch was ordered when the environment out outside of acceptable launch criteria. It was way too cold outside. The engineers who knew the system were frantically urging not to launch. Managers chose to ignore the experts and design limitations.
Thanks for the clarification
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
Does anyone know what font SpaceX uses for its broadcasted telemetry displays? I've tried whatthefont, et al but to no avail.
Actually, the law you refer to gave NASA an exemption but management chose to go green and it cost them the lives of those astronauts. Wikipedia
As I recall, one shuttle (Challenger) blew up on assent because the solid rocket booster ruptured at the seams and the resulting blowtorch ignited the external fuel tank. The second shuttle (Columbia) was struck during ascent by a piece of foam debris that dislodged from the external fuel tank and blew a hole in the leading edge of one of the shuttle's wings. The ablative tiles on the shuttle never caused a catastrophe.
It wasn't saturated in water ice. It didn't need to be. At 500 MPH relative speed, even plain old foam is quite damaging enough if it hits the wrong place. It hit the wrong place.
(Seriously, a foot or so to either side of where it did hit and there would have been a heavy aluminium support bracket behind the relatively fragile carbon-carbon leading edge. It would probably have cracked it either way, but wouldn't have left the gaping hole that let superheated air in.)
They've already returned first stages to land near the launch site. Three of them, I think. It depends on the mission and how much fuel they have after they get the second stage to where it needs to be (which in part depends on payload mass).
With Falcon Heavy, the two outriggers will return to launch site, the central core will continue further down range so probably do a drone ship landing.
Exactly the point. The most expensive part is never the part that goes to orbit. It's the part that launches the part that goes to orbit to an altitude and velocity where it can achieve orbit.
Kneel Before Christ!
Nope. Technicians do maintenance work according to instructions prepared for them by engineers. Engineers design. Re-design was necessary.
Bruce Perens.
I don't think you understood the issue you were replying to.
Bruce Perens.
But they skimped on the maintenance, allowing tiles to get loose. Over time they loosened and fell off, resulting in major catastrophe.
This statement is entirely false.
The Space Shuttle had many things wrong with it, but tiles getting lose and falling off wasn't the source of any catastrophe.
The 5 shuttles were supposed to fly once a week. That should have been about 5000 missions in its lifetime. Where the fuck do you idiots with your "135 flights is reusable" come from?
The second crash was.
But the lame thing about is: some guys had ideas how to change the reentrance path, which might have saved the vehicle and the crew, but some dick heads refused to try it. Knowing that the chance to survive without a change was basically only 1% or lower.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Is there some source out there that says how much of the rocket is re-used and how much is replaced with new parts? I would like to know what percentage is "original equipment" vs. how much is new. I would also be interested in knowing what the regeneration process is like in general.
I believe the two of you are looking at the engineering/maintenance problem from different perspectives. From a managerial perspective, the two are the same. You can trade one for the other, with money spent, and you do your calculations. From a technical perspective, they are quite different. Maintenance only repeats the same thing, restoring it to when it was new, but does not change it to something better. Re-engineering it would improve it so it is better than what it was when it was new.
Ol' Rick Dawson had a farm EIEIO
Well hopefully, the can continue to be reused, more than once or twice, because they'll lose a good chunk of that economic advantage if they fail with a $200 - $400 million satellite on-board on their 3rd or 4th flight.
Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
But then he says shit like hyperloop and super-speed tunnel boring and colonize Mars.
Yes he does. What's your point? Just because he hasn't actually completed those things yet he shouldn't talk about them? Seriously, what is wrong with trying to do amazing things? I feel pretty confident that unlike you (and me) he actually might make those crazy ideas happen. Probably not tomorrow but it took SpaceX 15 years to land a booster twice. Might take a little longer to get to Mars... He's working on hard problems that actually matter and making real headway on them. Fifteen years ago you probably scoffed at him starting SpaceX too. Personally I can't wait to see what he does in the next 15 years.
Seriously folks. If you aren't impressed by what Musk has done then you either don't understand it or are just trying to be too cool for the room because... reasons. You don't have to like the guy but you have to respect the hell out of him.
are so obsessed with identifying and calling out anything that looks like a "Steve Jobs Reality Distortion Field" that you are unable to acknowledge that we are witnessing the future happening.
Elon Musk is indisputably a tech visionary--or else that phrase has no meaning at all.
BTW: so was Steve Jobs. It doesn't make you "immune to groupthink" to claim otherwise, it makes a fucking idiot.
The problem is that he's got a mini version of the Steve Jobs Reality Distortion Field. He's got University students enthusiastically developing prototypes, when professors should be looking at this and saying, "bunk" for all sorts of sound engineering reasons.
Arthur C Clarke once said "If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong."
Point is don't be that guy. You're criticizing the guy who is actually making real progress on hard problems and willing to literally put his money where his mouth is. Unless you have done the same cut him some slack. No, not everything he tries will pan out but that doesn't mean it isn't worth looking into. Working on something like hyperloop is a much better use of student's time than making yet another useless/redundant app for smartphones.
Wrong on both counts. The wing leading edge damage on Columbia was caused by a chunk if icy insulation falling off the frozen external tank, which was full of LOX. And nobody suggested changing the re=-entry path because nobody suspected there was a hole. Because the mission did not go to the ISS there was no visual inspection of the Shuttle before re-entry. Retrospective analysis of the flight data did show a small rise in temperature inside the damaged wing after launch as the craft exited the atmosphere, but it did not catch anyone's attention at the time.
Learn to read.
The shuttle crashed because tiles where missing.
I did not mention why they are missing, yes, they where destroyed by the foam/ice that hit the wing before launch.
What has that to do with my post?
And nobody suggested changing the re=-entry path because nobody suspected there was a hole. /. I guess you find it with the search function ...
That was in the news after the crash. In my country at least. Blame your news feeds if you have not heard about it. The NASA guys who had suggested a change in reentry path were fired shortly afterward. That was covered here in
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Minor quibble: the O-Ring performed as designed - it was just that the launch was ordered when the environment out outside of acceptable launch criteria. It was way too cold outside.
Minor quibble on your minor quibble. The O-ring actually suffered from partial burn-through on every launch. It wasn't actually designed to do that as there was putty at the joints that was supposed to stop it entirely. They just decided that it wasn't a problem since it wasn't burning all the way through. Richard Feynman ripped them a new one in his report on Challenger over the opinion that burning only a third of the way through meant that they had "a safety factor of three".
The cold weather that it wasn't rated for made it much worse than usual, of course.
And nobody suggested changing the re=-entry path because nobody suspected there was a hole.
Actually, quite a few people suspected a hole, but they were shot down by management. Look up Rodney Rocha and his struggle to get satellite pictures taken of the wing.
Rebuilding the Shuttle's SRBs also included separating them back into separate sections and putting them into a press to bend them back into shape because the torque transmitted through the hold-down bolts in the skirts bent them out of shape. Before Challenger NASA changed the liftoff timing to hold the shuttle down for longer because the angular momentum was causing enough of a lateral shift at release for the Shuttle to hit launch structures which was breaking things. This resulted in an increase in torque applied to the SRBs bending them further out of shape. If you watch the video of the Shuttle prior to liftoff, you can *see* the entire structure bending.
In theory sections which required too much pressure to be bent back into shape were discarded but at some point they added another jack to force them into shape. I am sure those sections had nothing to do with what happened to Challenger.
What's your source for most of the parts on the srb's needing to be replaced? The srb's were made of aluminum and titanium, sea water is hardly corrosive to them. And they've been reusused for nearly 40 years.
Feynman's report discusses one aspect of the SRB building which he found disturbing. The separate sections get bent out of shape and have to be pressed to make them circular again. In the original design specifications, if the force to bend them back into shape was too great, they were suppose to be discarded but at some point (after NASA changed the launch timing by extended the hold-down time) too many were failing so they started ignoring that.
Low mileage. Only 15 million miles, one owner.
They'll launch it from the drone ship :)
Now THAT would be impressive
Pain is merely failure leaving the body
To be fair to NASA et al, a lot of their costs and processes are related to public oversight and government contracting in general. To the degree that NASA is an ineffective organization it's mostly at the dictum of Congress.
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
I really like that Slashdot is so ready with primary sources. Things like this are why I keep coming back here. That, and comments like, "But hey, what do I know. I only ran those propulsion plants for a couple of years."
Those who advocate genocide deserve every protection afforded by law, and none afforded by common human decency.
You ignore that uber-important word "probably".
Not remotely. We cannot prove a negative which is why that word probably is in there. Sometimes the elderly scientist is right when he says something is impossible. But I fear you missed my point.
There's a Very Big Difference between electric cars and reusable rockets (which is "just" very, very hard) and:
Yeah, yeah, they're tough problems but so what? It's cute how you so casually dismiss them as impossible. You proclaim that these other problems are somehow more intractable than the ones Musk has been working on as if it is axiomatic. You're akin to that elderly professor declaring it to be impossible and odds are you are almost certainly wrong. Worse, like me, I'm pretty sure you aren't an expert in any of these fields or at most in one of them. I've been around long enough to realize that few problem are impossible as long as they don't directly violate a known law of physics as we currently understand them. The constraints are usually more economic than technical.
1) Colonies (not research stations, but *colonies*) on a dead planet (there's a darned good reason why it's dead which gets 40% less sunlight than the Earth),
Self sustaining colonies on Mars are going to take centuries to really happen baring some technological miracles. But getting boots on Mars and having some sort of presence there should only take decades and really is a political/economic problem more than a technical one. The technical problems are serious but do not appear intractable and I'm pretty sure Musk is well aware of the challenges. The major limitations of colonizing Mars appear to be mostly economic. And Musk is working on solving THE major economic hurdle in doing it (cost to orbit) and he's made considerable progress. Every other problem in colonizing Mars follows from that one. For example there is little point in working on developing shielding for the trip there unless you can get to orbit cheaply enough to make the trip feasible. Yes Musk has talked about colonizing Mars and some of his time lines are to all appearances unrealistically optimistic but that doesn't make him wrong in the big picture. It just means it will take longer than he hopes. If SpaceX gets cost to orbit low enough a Mars colony becomes almost a certainty because either economic profit motive or geopolitics (or both) will almost certainly make it worthwhile. I feel reasonably confident that there is something economically valuable to be had somewhere on an entire undeveloped planet.
Imagine for a moment how much progress we could make on exploring the solar system if NASA and the defense department swapped budgets. NASA gets about $18 billion per year. The entire Apollo program in 2016 dollars was around $110 billion spread over a decade. We spend $600 PER YEAR on the US military. That's 5+ fully funded Apollo programs per year with more money left over than NASA's current budget. Our pace of progress on this is a economic choice, not a technical limitation.
2) boring stable tunnels at high speed through geologically highly unstable ground, and
"High speed" is something of a relative term here. Current boring technology goes "slow" because insufficient engineering effort has gone into making it go faster. Why? Again, economics. The mere fact that ground is unstable in places does not make tunneling through it at a faster pace than we currently do an intractable problem. Indeed, improving the speed of tunnel boring seems to be rather low hanging fruit for someone with the resources to seriously work on the problem. The problem will be in financing the tunneling projects, not in making a better tunnel boring machine.
Musk is interested in this technology because it has the potential to solve a key traffic issue which is that we have 3 dimensional cities but a (mostly) 2 dimensional transportation system. Flying car
When something is a matter of engineering, and not physically impossible, I like to be a little slow before calling it impossible. First, I want to check and see if anyone's actually doing it.
Quite right. Most of the problems we face aren't limited so much by technology but by economics and/or politics. Imagine for a moment what would happen if NASA and the Defense Department swapped budgets. On a short enough time scale all problems are impossible. On a long enough time scale very few problems are intractable. The rate at which you can get from impossible to feasible is usually a function of the economic resources applied to the problem.